After a few "mild" attempts on each other's lives, fueled by a mutual sense of betrayal, the marital spat culminates in a high-octane fight in the Smith house. After a long, evenly-matched fight, with their house shot to shambles, they wind up with guns in each other's faces. John balks, and lays his gun down; Jane finds she cannot shoot her spouse either, and both succumb to their love instead. Mr. and Mrs. Smith reunite and rediscover each other.
The newly-rekindled Smith partnership is quickly threatened by their employers, who have now decided to eliminate the couple. John's best friend and coworker, Eddie (Vince Vaughn), turns down a bounty of $400,000 for each Smith, but John and Jane find themselves under fire from an army of assassins. Fending off an attack which blows up their house, the Smiths steal their neighbor's minivan and successfully destroy three pursuing armored cars of attackers, all while bickering over their fighting styles and newly-discovered personal secrets.